This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Systemic Lupus Erythematosus (SLE) is a prototypic systemic autoimmune disease that disproportionately affects women of child-bearing age. We will obtain specimens by leukophoresis or venipuncture from lupus patients and healthy subjects to study the estrogen-estrogen receptor pathway in T lymphocytes.